Web folder protection apparatus and method

ABSTRACT

An apparatus and method for detecting jam-ups in a web folder used with high speed press printing presses. The apparatus includes a pair of fluidic sensing devices located in close proximity to a final run out conveyor for the folder. The sensing devices are adapted to sense the presence or absence of folded signatures at the location where signatures are deposited onto the run out conveyor and at a location a short distance downstream thereof and to individually activate an emergency stop circuit for the press and other protective or alarm means when an absence of signatures is sensed at one of the locations.

United States Patent 1191 r1 1 3,822,877 Littleton July 9, 1974 [54] WEB FOLDER PROTECTIQN APPARATUS 3,620,526 11/1971 lles et al. 271/56 X AND METHOD Primary Examiner-Joseph S. Reich [75] Inventor: F. John Littleton, Effingham, Ill. Assistant Examiner A l Heinz [73] Assignee: World Color Press, Inc., Maryland Att y, g or Firm-Wolfe, Hubbard, y ig,

Heights, Mo. Voit & Osann, Ltd. [22] Filed: July 31, 1972 [57] ABSTRACT PP NW 71 An apparatus and method for detecting jam-ups in a web folder used with high speed press printing presses. [52] U S. Cl 270/56 The apparatus includes a pair of fluidic sensing devices located in close proximit to a final run out con 51 1m. (:1 B65h 43/02 Y [58] Field Of Search 270/56, 86, 42; 271/56 "eyor the The sensmg devlces adapted to sense the presence or absence of folded signatures [561. N1 g E $135,,3323:assesses;5212::221222: U TED TAT S AT NTS downstream thereof and to individually activate an 654,284 SCOII..... emergency top ircuit for the press and other protec- 5,33 1 lsqtonglmukml 273/7503; tive or alarm means when an absence of signatures is oo o e a 2,940,751 6/1960 Buss 270/69 sensed at one of the locanons' 3,133,481 5/1964 McCormick et a1 271/56 X 7 Claims, 3 Drawing Figures z; z/ (V! Z! a! 1/; Q JV Z! 11; "I Q X JIZ (7/ 21/ O 1/4 I 12; 0% (67 if; M .fl'

- "1 WEB FOLDER PROTECTION APPARATUS AND METHOD DESCRIPTION OF THE INVENTION The present invention relates to all folders used with high speed web type printing presses, and more particularly to an apparatus and method for protecting such folders from damage resulting from paper jam-ups.

High speed web type printing presses are often fitted with a folder to fold and cut the web into booklets (also called signatures) which are delivered upon a delivery conveyor. There are numerous points within the folder where a booklet may go astray and fail to be delivered upon the conveyor, thus causing an immediate and often destructive jam-up. For some years it has been conventional to employ various jam-up detection devices, such as microswitches connected to mechanical arms, gates and the like, at various points within the folder so as to be actuated by a jam-up and to shut down the press. Typically, such switches are connected to the press stop circuit, and trigger an emergency stop when actuated.

Unfortunately, these'prior jam-up detection devices have many shortcomings. For one thing, there is an inevitable time delay between the occurrence of the jamup and the stopping of the press, i.e. at high press speeds the folder continues to be fed a considerable amount of paper after the jam-up switches have been activated even while the press is rolling to a stop. As a consequence, layers of paper become wrapped around and are very difficult to remove from the folder cylinders, thus causing considerable and expensive down time. Many times the paper build up within the jammed folder is so severe that the paper rollers or guides become bent or otherwise seriously damaged so that they are no longer useful.

A further problem often encountered with conventional jam-up detection devices is the fact that these devices themselves often become bent or otherwise damaged as a result of a folder jam-up. As a consequence the press operators often disable these protective jamup switches (as by wiring or taping them) to render them inoperable so that they cannot become bent or damaged by a jam-up and therefore cannot themselves be the source of a shut down. Yet another disadvantage of conventional jam-up detection systems is that a large number of switches or the like are required to provide some semblance of adequate protection, and it is necessary to place such switches in each path followed by the various streams of booklets as they proceed through the folder. It is not uncommon to find a dozen or more such microswitches in use within a single folder, and even then there inevitably are locations within the folder which are not protected by such switches and therefore which are vulnerable to a jamup.

It is a principal object of the invention to provide a simple yet effective folder protection apparatus and method which will detect jam-ups which occur anywhere within a folder, rather than only at certain locations therein. It is a further object of the invention to provide such an apparatus and method which utilizes jam-up sensors located at a single position within the folder and which function to activate the emergency stop circuit of the press whenever a folded booklet fails to be sensed by the appropriate sensor.

Yet another objectof the invention is to provide a web folder protection apparatus and method which reduces the aggravation of press jam-up to a minimum by immediately detecting such a jam-up, by activating the press emergency stop circuit and/or a warning light or buzzer, and by activating a web severing device located at the point where the web enters the folder to immediately sever and thereby stop the supply of paper to the folder. Still another object is to provide such an apparatus and method which also employs a web deflector device to deflect or divert a severed oncoming web away from the folder in the event of a jam-up.

Other objects and advantages of the invention will become apparent from the following detailed description and upon reference to the accompanying drawings, in which FIG. 1 is a schematic diagram showing an illustrative web folder protection apparatus embodying the present invention;

FIG. 2 is an enlarged, cutaway, fragmented elevational view showing an illustrative arrangement of sensors in conjunction with a folder delivery cylinder and delivery conveyor which may be utilized in carrying out the invention;

FIG. 3 is a schematic view showing the pressurized air flow to an illustrative sensor used in carrying out the invention, and the manner in which the sensor trips an electric shut down switch for the press.

While the invention will be described in connection with certain preferred embodiments, it will be understood that it is not intended to limit the invention to these particular embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalent arrangements as may be-included within the spirit and scope of the invention as defined by the appended claims.

Turning now to FIG. 1 of the drawings, the invention is there shown illustrated in connection with an illustrative'folder 10. As used herein, the term folder" refers to all of the equipment used to make the folds in the web, and to cut the product from the web as well as the final conveyor which carries the folded products away from the press. In theillustrative folder 10, which is a triple delivery type, the paper web 12, slit longitudinally into three ribbons, passes in sequence over a tri- I angular former blade 14, past web web,8c severer 15,

past a severed web deflector l6, and between a pair of cut-off cylinders 18 and 19. From the cut-off cylinders 18, 19 the cut-off portions (called signatures) of the three web ribbons pass in series through e7 separate folding and delivery arrangements (aisles), designated in the drawings by reference numerals followed by the letters a, b and c, respectively. Thus, the signatures are carried to a firstslowdown cylinder 20a, 20b or 200 via transfer cylinders 21a, 21b or 210, thence pass to a second slowdown and delivery cylinder 22a, 22b or 220, and ultimately to a delivery conveyor 24a, 24b or 24c. Conventional uphill transfer nips 23a, 23b or 23c are shown in running contact with the first slowdown cylinders 20 a, 20b and 200.

In operation, the paper web 12 travels over the top and down across the face of the former blade 14, which by reason of its triangular shape gives the web its first fold. The design of the former blade 14 is such that the web, which is traveling horizontally when it approaches the former, becomes folded and travels vertically when it leaves the former. Usually a driven roller located at the top of the former (RTF roll), not shown in the drawings, pulls the web over the top of the folder blade 14. As the web passes downwardly from the top to the base of the former blade 14, it wraps around the blade and the outside edges of the web are brought together. The former blade thus changes the direction of travel of the web from horizontal to vertical and at the same time imparts to the web its first fold. This first fold is a triangular fold with the point of the triangle being at the center fold of the web. A pair of guide rollers 25, 26 (RBF rolls) are provided near the base of the former blade 14 to hold the web taut behind the blade. Located just in advance of the-cut-off cylinders 18, 19 are a pair of driven main nipping rollers 28, 29 which pull the web down across the former blade 14 and move it on through the balance of the folder apparatus. These rollers also function to crease the fold in the web as the web leaves the former blade.

After leaving the main nipping rollers 28, 29 the folded web passes between the cut-off cylinders 18, 19 which cut the paper from the web. Typically, as the cutting cylinders 18, 19 rotate, the web is pulled between them and knives carried by these cylinders push through and cut the web intopage lengths or into the desired booklet size. Following cut-off, the cut portions of paper receive a second fold by a tucker blade (not shown) which pushes the product between a pair of rollers (also not shown) to complete the folding operation. The folded booklets or signatures pass around the various cylinders described previously, and finally around the second slowdown and delivery cylinders 22a; 22b and 22c from which they are released one at a time by cam-operated grippers 27 (see FIG. 2).

Stops 30a, 30b and 300 are provided on the press framework (not shown) in the respective aisles for terminating rotary movement of the booklets (designated 31a, 31b, 310) about the delivery cylinders 22a, 22b and 22c, and for depositing them on top of the delivery conveyors 24a, 24b and 24c. The stop 30a takes the form of a roller located above the conveyor belt 24a near the discharge of the delivery cylinder 220, while stops 30b and 300 are bar shaped and located beneath the delivery cylinders 22b and 220. Ultimately the folded paper booklets 31 come to rest on the delivery conveyors 24a, 24b and 240 one on top of the other, but each offset from the one below it by an inch or so (due to travel of the conveyor). The conveyors 24a, 24b and 240 as shown include endless belts 32a, 32b and 320, driven by sprockets 33a, 33b, 330.

In carrying out the present invention, a pair of tluidic sensing devices 34a and 35a, 34b and 35b, and 340 and 35c, respectively, is located within each folder delivery conveyor 24a, 24b and 24, each such pair being spaced apart along the conveyor and disposed just beneath the top conveyor belt surface. Each of the illustrated devices 34, 35 which may be of a known type such as sold by Corning Fluidic Products under the trade name 0. J. Sensors, constitutes a pneumatic proximity sensor and includes an air emitter 36 which produces a specially (e.g. conically) shaped pattern or stream of air 37 (see FIG. 3) which tends to converge as it leaves the emitter. The location of each sensor 34, 35 causes the air stream 37 to impinge directly upon the underside of the stream of booklets 31 emerging from the last folder cylinder 22 and being placed upon each delivery conveyor 24.

When an object such as apaper booklet 31 is present on the conveyor 24 within sensing range (up to about an inch from the face) of each sensor 34, 35, it causes the air stream 37 to diverge and be altered in a known manner. If however a booklet 31 does not appear on the conveyor 24, as would result from a jam-up, a change occurs in the air pattern 37 which results in a change in output from the sensor 34, 35. This change in output is detected by a pneumatic to electric interface switch 38, the output of which is connected to an electrical switch 39 operative to close an emergency stop circuit (not shown) and thereby shut down the press drive, and/or operative to actuate the web severer 15 to sever the paper web entering the folder and thereby avoid further jamming the folder. The switch 39 may also operate a warning lamp or buzzer circuit (not shown) to warn the press operator of the jam-up. (As used herein the term jam-up denotes paper congregated in an incorrect position anywhere throughout the folder.

Thus it is seen that the sensors 34, 35 are responsive to and detect a paper or no paper condition. In the normal condition, a paper booklet 31 is present on the conveyor 24 and the press continues to run. Should a jam-up occur anywhere in the folder, a no paper condition is immediately created over the sensor 34, 35, and an electrical signal sent back to the web severer 15 to cut off the traveling paper web entering the folder as well as to activate the emergency stop circuit of the press and shut down the press completely. Preferably, it is also desirable to provide the web deflector 16 which may be electrically interconnected with the severer 15, so that upon activation of the severer the deflector is also activated to swing into the path of the traveling web and divert the severed web away from the main nipping rollers 28, .29, and thereby avoid further jamming of the folder.

The net result of this is that the sensors 34, 35 readily detect the absence on the conveyor of even one folded booklet 31, leaving only a small gap in the moving stream of folded booklets. If one folded booklet fails to appear in its place in the stream, the sensor 34 or 35 responds by tripping the switches 38 and 39 to actuate the severing device 15 located upstream. Actuation of the severing device 15 then causes the deflector 16 to shift from an inactive to an active position crosswise of the normal path of the web 12, so that the paper web being fed into the folder rollers 28, 29 is diverted onto the floor or someplace else where no damage can be done to the folder. Then, since the detector system is electrically interconnected with the emergency stop circuit for the press, the entire press shuts down if one folded booklet 31 fails to emerge from one of the folder delivery cylinders 22.

It is advantageous that each delivery conveyor be furnished with two spaced apart sensors 34, 35 to accomplish the above. The first sensor 34 may be set so that upon activation it stops the press and/or operates the severer 15. Then if the second sensor 35 detects a no paper condition, it may actuate a lamp circuit or a busser, and then perhaps a few seconds later the press emergency stop circuit may be activated. importantly, should a jam-up occur in the vicinity of the first sensor -34, which might not be detected because that sensor would detect the presence of paper, the second sensor 35 would then shut the press down. And the few seconds lag between the time of the jam-up and activation of the second sensor gives the press operator a chance to manually correct the jam-up during this interim.

Preferably the sensors in the b and c aisles (i.e. sensors 34b and 35b, and 34c and 350) are spaced a minimum of one signature length apart, plus about one inch. In the folder delivery arrangement shown in aisle a, the distance between sensor 35a and the center of the stop roller 30a is preferably about one signature length (plus about one inch), while the distance between the sensors 34a, 35a themselves is about two signature lengths (plus about an inch).

Thus it is seen that the instant invention detects a paper jam occurring anywhere in the folder system, and immediately brings about shutdown of the press and severing of the paper web to prevent serious damage to the folder. And the invention does this by utilizing specially located fluidic sensing devices which advantageously have no moving parts to become damaged or fouled or subject to vibration.

The invention thus advantageously'avoids the use of multiple mechanically actuated switches which heretofore have been placed at numerouslocations throughout the folder, and which are subject to damage and tampering. The prior mechanical switches have also been subject to vibration causing them to be actuated inadvertently thereby resulting in needless costly press shutdown.

The invention also avoids reliance upon photoelectric means for detecting jam-ups, which are invariably rendered ineffective inasmuch as the immediate vicinity of the press folder usually abounds with paper dust, oil mist, and other contaminants which tend to foul or otherwise render ineffective photoelectric detection devices. The fluidic sensing devices utilized in carrying out the invention are kept clean by the constant passage of air therethrough, and in the folder protection apparatus of the invention provide a degree of jam-up detection reliability heretofore unattainable.

While the invention has been illustrated and described in connection with a former type folder, it will be understood that it may be employed as well with a jaw type folder, or a combination folder. Indeed, the invention may be employed in connection with any equipment wherein the materials to be detected are so light in weight, or the conditions surrounding the detection equipment are such, that mechanical microswitches are inadequate or ineffective.

In some installations the motor drive for the delivery conveyor is separate from the main press drive motor. When this is the case, a stoppage of the delivery conveyor will result in both sensors 34 and 35 detecting the presence of paper booklets on the conveyor and thereby failing to activate the press drive shutdown circuit and the web severer. In order to insure detecting a jam-up caused by such a delivery conveyor stoppage, a centrifugal switch may be connected to the conveyor drive motor to shut the main press drive motor down and/or activate the web severer. In this way the centrifugal switch detects a stoppage of the conveyor drive motor and thereby activates the emergency stop circuit for the press.

I claim as my invention:

1. In a high speed web press folder including means for imparting a fold to a paper web, cut-off cylinders for cutting the folded paper web into sections, folder cylinders for imparting a second fold to the cut-off paper sections and thereby producing folded paper booklets, and a run-out conveyor including a moveable belt disposed below said folder cylinders for receiving from the folder cylinders successive folded paper booklets in partially overlying relation and carrying said booklets laterally away from the folder, an apparatus for detecting paper jam-ups anywhere in the folder and protecting the folder from damage comprising, in combination, fluidic sensing means immediately adjacent said run-out conveyor belt at the approximate location where said folded booklets are received by said conveyor for sensing the presence or absence of folded booklets on said belt at that location, said fluidic sensing means including an air emittor for directing a stream of air toward said conveyor belt at said booklet receiving location, a web severing device located upstream of the cut-off cylinders and adapted to be caused to sever the web, and means responsive to said fluidic sensing means for actuating said web severing device to cause it to sever the web in response to the absence of folded booklets on the conveyor belt at said receiving location.

2. An apparatus as defined in claim 1 including means for shutting down the press and in which the means responsive to the fluidic sensing means for actuating the web severing device also causes said shut down means to stop the press.

3. An apparatus as defined in claim 1 including means responsive to said fluidic sensing means for actuating a warning light or buzzer in the event of the absence of folded booklets on the conveyor.

4. An apparatus as defined in claim 1 in which a second fluidic sensing means is located in close proximity to said conveyor belt at a location downstream from said first fluidic sensing means, said second fluidic sensing means including an air emittor means for directing a stream of air to said conveyor belt at said second location, and said air emittor means of said first and second sensing means being spaced apart a distance equal to approximately the length of one of said folded booklets.

5. An apparatus as defined in claim 4 in which said air emittors each are located below the conveyor belt and direct a stream of air toward the underside of said belt.

6. An apparatus as defined in claim 4 including an alarm means, and said second fluidic sensing means being operable to activate said alarm means upon sensing the absence of folded booklets on said conveyor belt at said'second location and to activate said web severing device after a predetermined relatively short interval following activation of said alarm means.

7. A method of detecting paper jam-ups in a printing press web folder which folds and cuts paper signatures from a continuous web and discharges successive folded signatures onto a moveable belt of a run-out conveyor with said signatures being deposited onto said belt in partially overlying relation for lateral transfer away from said folder comprising the steps of sensing the presence or absence of folded signatures at the approximate point on said conveyor belt where said folded signatures are discharged onto said bolt, sever-.

ing the web entering the folder in response to the sensed absence of folded signatures on said conveyor at said discharge point, sensing the presence or absence of folded signatures on said run-out conveyor belt at a point downstream from said discharge point if there is no absence of signatures at said discharge point, activating an alarm means in response to the sensed absence of folded signatures at said downstream sensing point, and stopping the operation of said folder after a predetermined relatively short interval following activation of said alarm means. 

1. In a high speed web press folder including means for imparting a fold to a paper web, cut-off cylinders for cutting the folded paper web into sections, folder cylinders for imparting a second fold to the cut-off paper sections and thereby producing folded paper booklets, and a run-out conveyor including a moveable belt disposed below said folder cylinders for receiving from the folder cylinders successive folded paper booklets in partially overlying relation and carrying said booklets laterally away from the folder, an apparatus for detecting paper jam-ups anywhere in the folder and protecting the folder from damage comprising, in combination, fluidic sensing means immediately adjacent said run-out conveyor belt at the approximate location where said folded booklets are received by said conveyor for sensing the presence or absence of folded booklets on said belt at that location, said fluidic sensing means including an air emittor for directing a stream of air toward said conveyor belt at said booklet receiving location, a web severing device located upstream of the cut-off cylinders and adapted to be caused to sever the web, and means responsive to said fluidic sensing means for actuating said web severing device to cause it to sever the web in response to the absence of folded booklets on the conveyor belt at said receiving location.
 2. An apparatus as defined in claim 1 including means for shutting down the press and in which the means responsive to the fluidic sensing means for actuating the web severing device also causes said shut down means to stop the press.
 3. An apparatus as defined in claim 1 including means responsive to said fluidic sensing means for actuating a warning light or buzzer in the event of the absence of folded booklets on the conveyor.
 4. An apparatus as defined in claim 1 in which a second fluidic sensing means is located in close proximity to said conveyor belt at a location downstream from said first fluidic sensing means, said second fluidic sensing means including an air emittor means for directing a stream of air to said conveyor belt at said second location, and said air emittor means of said first and second sensing means being spaced apart a distance equal to approximately the length of one of said folded booklets.
 5. An apparatus as defined in claim 4 in which said air emittors each are located below the conveyor belt and direct a stream of air toward the underside of said belt.
 6. An apparatus as defined in claim 4 including an alarm means, and said second fluidic sensing means being operable to activate said alarm means upon sensing the absence of folded booklets on said conveyor belt at said second location and to activate said web severing device after a predetermined relatively short interval following activation of said alarm means.
 7. A method of detecting paper jam-ups in a printing press web folder which folds and cuts paper signatures from a continuous web and discharges successive folded signatures onto a moveable belt of a run-out conveyor with said signatures being deposited onto said belt in partially overlying relation for lateral transfer away from said folder comprising the steps of sensing the presence or absence of folded signatures at the approximate point on said conveyor belt where said folded signatures are discharged onto said bolt, severing the web entering the folder in response to the sensed absence of folded signatures on said conveyor at said discharge point, sensing the presence or absence of folded signatures on said run-out conveyor belt at a point downstream from said discharge point if there is no absence of signatures at said discharge point, activating an alarm means in response to the sensed absence of folded signatures at said downstream sensing point, and stopping the operation of said folder after a predetermined relatively short interval following activation of said alarm means. 